This invention relates generally to lasers and more particularly to recirculating gas lasers having an airtight housing in which are disposed the working parts of the laser.
Flowing gas lasers are known in the art. Examples of such lasers are disclosed in the Wilson U.S. Pat. No. 3,543,179; the Daugherty et al U.S. Pat. No. 3,702,973; and the Hoag U.S. Pat. No. 3,921,098. The Daugherty et al and Wilson patents provide an excellent discussion of background laser technology and the Hoag patent provides an excellent discussion of an early form of gas laser, the working parts of which are disposed in a sealed housing. The Wilson, Daugherty et al and Hoag patents are incorporated herein by reference as if set out at length.
One prior art technique requires the construction of the various working parts of flowing gas laser systems to be structurally sound to withstand a high pressure differential. Each part or component must withstand ambient conditions while maintaining a reduced or increased pressure inside the flow area, as well as performing its function in the system. In closed flowing gas lasers, the lasing medium or gas is continuously flowing through the flow path in a circulating fashion. Accordingly, the working parts must act as a guide, as well as withstand the pressure differential between the flow area and the external atmosphere. The respective component parts must be tightly sealed so that extraneous gas leaks will not develop and poison the system, i.e., if oxygen or some other contaminant from the atmosphere leak into the flow region, the system would be contaminated.
Another prior art technique as exemplified by the Hoag patent is based on the provision of an airtight housing to withstand the required pressure differential between the system and the atmosphere. The working components of the laser are mounted within the housing in combination with duct means surrounding the central portion of the housing to define a wind tunnel in which gas flowing in the wind tunnel can, in part, escape into the housing. This wind tunnel approach requires turning sections, transition from circular to rectangular sections, and diffusers with consequent high cost and difficulty of fabrication, high pressure losses and turbulence in the gas flow as it enters the lasing region and/or blowers.
Accordingly, it is an object of this invention to provide an airtight laser housing in which all of the working parts of the laser are mounted within one pressurized container.
Another object of this invention is to provide an airtight laser housing for a flowing gas laser wherein the housing may be easily maintained at reduced pressures and wind tunnel type gas directing means are not required.
A still further object of this invention is to provide an airtight laser housing containing the working parts of the laser wherein the housing is sealed from the external atmosphere and the lasing medium is caused to circulate within the housing with minimum pressure losses and minimum turbulence as the lasing medium enters the lasing region.